I've posted this on the firing line (I believe) in the past.
I have personally witnessed a .300 win mag 180 gr nosler fail on a head shot to a brown bear.
I'll save all of the gory details but here is the meat of the incident. The bear was shot head on at 30 yards in the tip of the nose.
You see gentelmen when bears are A. Charging or B. Just doing the I'm a cautious bear thing they tend to hold their noses up making the brain only accesable through the point of the nose. They generally do not hold their heads down.
Because of this and the geometry of a bear head (flat on top for the most part) a frontal brain shot is very difficult on a bear as the skull is held perpendicular to the ground making penetration darn near immpossible from the front with anything but the deepest penetrating heavy bullet. Now if the head is at any kind of angle it makes the brain more accesable however the bullet still has to make it through the xigomatic(SP?) process or cheek bones which are massive on a big bear.
In any case at the shot the bear rolled over onto his haunches sat up and chuffed out a huge ball of bloody snot and was gone into the brush all in a matter of 2 seconds or less. (Wounded bears seldom charge at the shot the trouble is usually encountered either following up on a bear in the thick stuff or surprising one in the thick stuff.)
About 5 days later another buddy of mine shot this bear killing it with a .375H&H using a 285gr grandslam through the shoulders at just over 100 yards. A one shot kill by the way. Though he did give it some insurance afterwards.
The reason we know it was the same bear was from the massive wound out the bridge of his nose about 3 inches from the entry. The 180 gr nosler launched at 3000Fps had hit the bear in the nose and instead of traveling straight to the brain encountered the massive bone structure of the nose/skull and was deflected out the top of the nose.
Heck a mere 17 inches more penetration and it would have done some good. On the other hand seldom will a good bullet out of a .375 or .416 or even a .338 not get full penetration on a bruin even after hitting bone.
So here's the gig yes it is techinacally possible to kill a bear with a .223. Not really all that difficult in fact on a relaxed side possing bear just pop him in the ear with a solid and that's it. To STOP a charging bruin with a frontal head shot with a .223 would be darn near immposible. You couldn't turn him with a body shot like you could with an adequate caliber and your chances of.................................................................
........................................!!!!!!!!!!!!!!!!!!!!!!!!!!
A. getting a bullet in the right place.
B. having that 55gr splinter get through nearly 20 inches of sinus bone and tissue to even touch the brain.
C. Even being able to get a shot off in the first place in any kind of cover are about 1 in a million. But like they said in dumb and dumber "so I guess there is a chance!"
As far as using buckshot Blain I think we've already discussed that one. Dude go get yourself some slugs for that scatter gun and quite trying to make little lead balls into lazer beams. They just ain't going to do it
